By Judicial Decree 13: Rules of Evidence

Betty Carroll thought she'd left her sordid past behind forever, now that she was the famous Wireless Schoolteacher, so when her old partner in crime showed up to blackmail her, she did what came naturally: she killed him. It was all downhill after that, until she hit bottom, and ended up in the infamous Rupert Caine's dungeon, being trained as a sex toy.

Halli Fairbourne believed she had to suffer for the killing of her sibling, even though it was an act of mercy, so she arranged to have herself convicted of homicide and judicially enslaved, then was bought for Caine, who would make sure she would suffer adequately.